Answer to Question #218195 in Physics for ran li

Question

A 25.0-kg child in Red Deer pumps herself on a swing when she kicks upward on the downswing, thus changing the distance from the pivot point to her centre of gravity from 2.40 m to 2.28 m.

1.The resonant frequency of her swing before the kick is: ___ Hz. (Give your answer with the correct number of sig digs and do no include units in your answer).

2.The resonant frequency of her swing after the kick is: ___ Hz. (Give your answer with the correct number of sig digs and do no include units in your answer).

Answer 1

1)

$$f_1=\frac{1}{2\pi}\sqrt{\frac{9.8}{2.4}}=0.322\ Hz$$

2)

$$f_2=\frac{1}{2\pi}\sqrt{\frac{9.8}{2.28}}=0.330\ Hz$$